It is known in the art that in order to provide shielding or filtration in association with radiation sources masking or shielding devices are required. Such shielding devices take on various configurations depending on the method of providing the shield, the size of the area to be shielded and the type of radiation source. Various radiation shielding configurations have been developed in connection with X-ray radiography to provide against the excessive exposure of the subject to radiation.
It is also known in rhe art that filtration or diffusion of radiation provides against excessive exposure of the subject. Various devices have been developed to filter the radiation generated in connection with X-ray radiography. All of these devices need to be mounted in close association to the source of the radiation in order to provide maximum shielding against, or filtration of, the radiation.
The prior developments of the inventors of the present invention are exemplary of the devices known in the art and teach the use of both a shielding means and a filtration means for providing either shield or a filter for the radiation generated in connection with X-ray radiography. These prior developments also teach the use of a specialized mounting means to cooperatively place the shield or filter in close association to the source of the radiation to provide maximum benefit to the subject in permitting the least amount of excessive exposure to unnecessary radiation. These developments are described in U.S. Pat. Nos. 4,266,139 and 4,472,637 and typify the present state of the art in this field.
It is an object of the present invention to carry these developments one step further and to provide a masking device to block all radiation from the radiation source not needed to cause an image to appear on an X-ray film for the specific area of the subject to be observed or inspected.
It is a further object of the present invention to provide a masking device which cooperates with the earlier developed shielding and filtering devices and the standard X-ray systems in use today.
It is also an object of the present invention to provide a masking device which is compact, easy to use, versatile and resilient to continued use and not quickly subject to irradiation from an X-ray radiation generating source.